In the production of precast concrete components, the method of fixing the formwork directly affects production efficiency, component precision, and overall cost. Currently, the two main technical approaches on the market—Shuttering Magnet and screw fixing—each have → each has their loyal supporters. So, which system is more suitable for your production line?

Basic Principles

 - Shuttering Magnet: Utilizing the strong magnetic attraction generated by high-performance permanent magnet materials, the template → formwork is firmly attached to the steel mold platform. Quick installation and removal are achieved by controlling the "on/off" of the magnetic circuit via a mechanical handle or rotating mechanism.

 - Screw Fixing: A traditional mechanical fixing method that uses bolts, nuts, washers, and other fasteners to lock the template → formworkto the mold platform (or to each other). This usually requires pre-drilled holes in the mold platform or formwork.

Core Performance Comparison

Why Magnetic Box Fixing Wins for Most Operations

 1. Speed that boosts capacity

On an automated line, every change of component dimensions means reconfiguring the formwork. With magnetic boxes, a single worker simply rotates a handle – no tools, no wrestling with nuts. That’s 5 to 10 times faster than screw fixing. If you change molds several times a day, those minutes add up to real output gains.

2. Consistent precision

Screw fixing suffers from “false tightening” – different workers apply different torques, and wrench arm lengths vary. During concrete vibration, bolts can loosen and the formwork can shift. Magnetic boxes deliver a stable, uniform holding force (typically 600–1500 kg per box) that doesn’t weaken with vibration. The result: better dimensional consistency, especially critical for composite slabs, wall panels, and anything with tight edge tolerances.

3. Longer mold table life

Your steel pallet is one of the most expensive assets in the plant. Screw fixing requires drilling and tapping hundreds of holes. After repeated use, threads strip and holes crack, and the pallet has to be downgraded or scrapped. Magnetic boxes need no holes at all – the pallet surface stays pristine, extending its service life by 2–3 times.

4. Lower labor strain

Workers no longer have to bend over to tighten dozens of bolts or lug heavy wrenches around. Magnetic boxes are light (typically 5–15 kg) and easy to handle. That reduces fatigue and makes the job accessible to a wider range of workers – a real benefit when recruiting and retaining staff is tough.

When Screw Fixing Is Still the Better Choice

Despite all the advantages of magnetic boxes, screw fixing hasn’t disappeared. Here’s why:

• Very low startup cost – A full set of magnetic boxes can cost tens of thousands of RMB, while a bag of bolts is just a few hundred. For a tiny shop or on‑site beam casting, screws are the practical way in.

• Irregular or non‑standard formwork – If the formwork has a complex shape with no flat, steel surface for a magnetic box to grip, screws can be placed exactly where needed.

• High‑temperature conditions – Some permanent magnets lose strength above 80 °C. If you’re making steam‑cured components and your temperature control isn’t reliable, screw fixing is safer. (But good‑quality magnetic boxes use neodymium magnets rated for 120 °C.)

• Non‑magnetic formwork – Magnetic boxes only work on ferromagnetic (steel) surfaces. If you need to secure wooden, aluminum, or plastic molds, you have no choice but screws.

Final Recommendation

For the vast majority of modern precast concrete plants, magnetic box fixing is the clear upgrade. The gains in efficiency, precision, and pallet life usually pay back the investment within 6–12 months – through reduced labor and longer equipment life.

Prioritize magnetic boxes if you produce:

• Composite floor slabs or double‑skin walls

• Precast stairs or balcony slabs

• Prestressed hollow‑core slabs

• Any high‑volume, highly repetitive standard components

Stick with screw fixing only in these special cases:

• Annual output below 5,000 m³ (small workshop)

• Frequent need to fix non‑magnetic or high‑temperature formwork

• Formwork shapes so irregular that magnetic boxes can’t be placed effectively

One last tip: Not all magnetic boxes are created equal. When buying, check the magnetic strength retention guarantee (at least 5 years), the durability of the on/off mechanism, and whether the design prevents accidental demagnetization. Invest once, benefit for years.